1. Field of the Invention
The present invention relates to telephone subscriber terminals in general, and in particular to those having a display screen. More particularly, it relates to a set capable of user interaction by means of soft-keys the definition of which may be downloaded through a thereto connected central office (CO). The set is, therefore, configurable in a limited way to permit remote, but user friendly operation, for banking, shopping, or such other interactive services as may be offered and/or supported by telephone companies and their customers.
2. Prior Art of the Invention
In U.S. patent application Ser. No. 07/733,027 filed Jul. 22, 1991 by G. Chaput et al, a method of transmitting data between a CO and a subscriber terminal is disclosed wherein data bursts may be transmitted to the terminal while off-hook, thus enabling the terminal to be in a data interactive mode at the same time while in voice communication mode.
In December 1992 an industry-wide standard protocol for Analog Display Services Interface (ADSI) was completed by Bell Communications Research Inc. to serve as a standard for voice and display (data) information to be transmitted between subscriber terminals and telecommunications switches or servers over the existing copper telephone lines (loops). This standard protocol also defines the formats for the large scrollable displays and softkeys to support new enhanced, interactive, services.